<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>固定窗口</title>
    <script src="../js/jquery-3.4.1.min.js"></script>
    <script>
        $().ready(function () {
            $("#keFu").css({"position":"fixed","right":"0px","top":"75%"});
        });
    </script>

</head>
<body style="height: 8000px;width: 3000px;">
<div id="keFu">
    <a href="#"><img
            src="https://www26.53kf.com/style/setting/ver06/img/icon/logo-skin/click_btn/clickbtn_4.png"
            height="100px" width="90px"></a>
</div>

</body>
</html>